Plate valve



sept. 7,1926. 1,599,281'

, F. VAN D. LONGACRE lPLATE VALVE Filed AIvD-ec. 8. 1925 2 Sheets-Sheet1 G1 "/JI-//H'x-w Sept. '7 ,1926.

F.. VAN D.-l oNGcRE PLATE VALVE Filed'nec. s', 1925 2 Sheets-Sheet 2 lIN VEN TOR. IdeuckIDLon' neue 3% HISATTD EY Patented Sept. 7, 1926, .Y

PATENT i FREDERICK VAN DU'ZER LONGACRE, or Yoivirnits,V NEW YORK.As'siGivoR To :Nenn` SOLL-RAND COMPANY, oF JERSEY orrnnnwannsnv; AooRPonATroNor :NEW

JERSEY.

i PLATE VALVE.

appneation fueainecember s, 1925. VSernin.- 74,o3s. f

This invention relates to luid compressors but more partieularlyto animprovement in valves for such compressors known to the art as platevalves. In suoli .valves a tliindisc or plate is adapted to lie, uponports arranged onv a valve seat and the operation of the valveconsistsin the vertical lift and fall of the dise in relation to thevalve seat.` Although there aresmany variations in the design of platevvalves, there is one disadvantage which is common to practically allvforms, which is the jar or` concussion between the valve discV and thevalve seat, when v thevalveis reti'irnedtoits'seat, for this concussion,besides making' the operation of the machine, noisy, also tends towardvbreakage of the valve. lIii-practically all types of voluntary valvesfor air compressors and the like where the movement ofthe valve iscaused by pressure differential, these valves in theiractual operationhave a degree of freedom of'action which causes them to come in Contactwith their back stops on opening and with their seats on closing in anirregular manner. That is, it is practically impossible to prevent somepart of aV valve plate from coming inV Contact with its seat ahead ofthe rest of the valve plate, and whereas in such a valve no provision ismadeto cushion the shockof this contact, the durability of the valve isgreatly reduced and there is a consequent reduction in the velocitylimitations that the valve would vbe capable of, could this beprevented. Considering the valve as a free agent, controlled by manyvariations in velocity through the ports and passages it will continuein the great majority of cases to open and close so as to produce thecontact at one part of ythe valve. What I'aim to do is toanticipate'this movement v and to cause it to take place ahead of theextreme velocity action lof the valve by the use of dier'entialspringing of the valve plate, having heavier springs at one locationthan at the other so that the valve will close due tospring effect priorlto the fulldrop in pressure where the heavier springs are-located andwill open prior to the full application of pressure, where the-lightersprings are located, thus causing the Contact at these locations onclosing and opening to occur` ahead of time, when the velocityconditions are much lower, whereby the consequent shock is much reduced.

T he object of inventiontherefore is toeliminateA one disadvantagecommon toA all plate-valves by adapting the valve to vseat atk A valve'allowed to seat in4 a haphazard fashion.y My invention consists intheAfeatures of novelty `and combination ofv elements described in thespecification, slety vforth in they i appendedv claim,and'illustrated'i'n the drawings in'w'hich* l Figure l isa transverseelevation of 'a complete discharge valve assembly showing the valveopen, l Figure 2 is a horizontal view of the valve disc itself withcoilspringsof different in-V itial tensions shown properly placedthereon,

Figure 3 -is' a transverse sectional' elevationfof amodified form of thevalve asseinbly, Y

tion of the valve assembly Vshowing my `iii- 60 In this way, whether thevalve is circular in form or rectangular, it will easeV downV upon itsseat smoothly and'compara-.itively silently and' there is no danger ofits being vcracked or broken, as thereis with a.

. Vso Figure 4 Ais a transverse sectional elevav vention applied to avcup-shaped annular i valve plate, i

Figure 5 is a transversesectional elevation of a strip valve embodyingmy invention, while, Y 1

f Figure 6 is a horizontal view of a section of the same strip valveassembly.

Referring to Figures landQ of tliedrawings, a-valve seat A, stop. plateB, and a valve disc C are'shown suitably held in .relation eachv to eachby means o f the valve bolt D and the ynut E. The valve seat isyprovided ywith three concentric sets of ports F aiid the valve disc Cis adapted to lieover and upon these ports. Recesses G" are cut in thestop plate B and are adapted lto4 containy coil springs whichV will bearupon the valve ldisc and hold -it to its seat.v .The

springsklrl are placed in the recesses G at the outer circumference ofthe` stop plate whilevsprings'J of considerably greater initial tensionthan the springs H areplaoed in the rvrecesses G nearer` the center orthe valve. In this way, the operation of the ino valve willv besuch thatthe compression in the cylinder Ywill force open the outer portions ofthe `valve disc against the small initial Vtension of theV springs'Hbefore itwill force open the center portions of the valve discagainstpthe greater tension of the wsprings J and upon its return to theval-ve seat, thevalve will seat beneath the springs J before its outerextremities seat beneath the springs H.

In Figure 3 the saine valve assembly as in Figure l is shown except thatthe springs have been reversed andas a result, in this case, the Vvalvelwill seat Yin operation at its outer*circumference before it will seatnearer its center. In Figure l the usual valve assembly is'shown inwhich a semitubu'la-r 'ring or cup-shaped form of valve isgu'sed, andtheheavy springs J vare placed on one side of they valve while the lightsprings "H :are 'placed Yon the diametrically opposite side with aresult that 'the valve will rock downupon its seat with that part o'ffthe' valve beneath the heavier springs J seating first. l

Figures 5 and 6 show myy invention as yapplied to the socalled stripvalve in which a thin rectangular and resilient strip C, used 'as thevalve proper, seats vupon the valve seat A, and is held in place by theback stop B, the two outer and lighter springs H and the central heavyspring J. As a result the central portion of the valve beneath the heavyspring J will seat before its extremities beneath the lighter springs H.i

My invention is not to be confined merely to the exact vforin describedin iny speciication or shown in the drawings as it is very evident thatone skilled in the art cou-ld 'devise various nieans for applying itaccording tothe circumstances involved.

l claimt- An improvement in plate valves for fluid compressorsycomprising a valve plate,-a stop plate, a bolt hold-ing said elementsin proper relation each to each, pockets in the said stop plate, andcoil springsin vsaid pockets adapted to bear upon and hold the valve.

upon its seat, the initial tension vof said coil 'springs `being'unequal and so arranged that a part or parts of the valve plate willseat in advance of its complete seating.

ln testimonyV whereof 'I have signed this specification. p n j FREDERICKvaniDUzER LoNcA-CRE.

